This invention relates to a rotary head assembly and, more particularly, to an improved assembly for resiliently supporting a transducer which is adapted to record and/or reproduce information during its rotation about an axis.
Rotary heads have found ready application in magnetic recording apparatus, such as video tape recorders (VTR) wherein at least one transducer, such as a magnetic head, is rotated about an axis to scan a record medium, such as magnetic tape, a magnetic sheet, or the like, to record information on and/or reproduce information from the medium. In a typical VTR apparatus, a pair of magnetic heads are spaced apart by 180.degree. and scan a circumferential slot, or gap, between upper and lower guide drums about which magnetic tape is deployed. In typical VTR apparatus, the rotary heads are effective to scan parallel slant tracks across the tape.
In many recording/reproducing processes, and in particular, during magnetic recording/reproducing in a typical VTR, the quality of the recorded or reproduced signal depends, to a great extent, upon the relative contact between the rotary heads and the scan medium. In particular, contact pressure is a significant parameter which has a great influence on the quality of recording/reproducing.
In conventional recording/reproducing apparatus, a rotary force is imparted to a drive member, and the heads are fixedly secured to the drive member. In a typical apparatus, the drive member may be in the form of a pair of oppositely disposed rigid arms which are joined to an axis of rotation, and respective heads are secured to the opposite ends of the respective arms. In this type of assembly, the heads are, of course, completely restrained from radial movement with respect to the rotary axis so that contact pressure between the heads and the scanned medium is determined solely by the tension of that medium. As a consequence thereof, if the medium, such as tape, is under high tension, then the resultant contact pressure, when considered in combination with the relatively high head speed, causes severe wear on the head itself, whereby the heads undergo rapid deterioration.
A head assembly has heretofore been proposed wherein contact pressure between the head and medium is not determined solely by the tension of the medium. This head assembly, described in U.S. Pat. No. 3,673,347, includes an arm which is pivotally secured to a rotary disc and which is adapted to support a magnetic head at its free end. When the disc rotates, centrifugal force is exerted on the head, whereby the rigid arm pivots to thus urge the head radially outward and into contact with magnetic tape. A spring has one end secured to the disc and its other end secured to the arm to thus limit the pivotal movement of the arm. Once the disc stops rotating, the spring causes the arm to pivot in an opposite direction so as to urge the head into a storage compartment.
In practice, the aforedescribed patented head assembly fails to prevent the heads from vibrating or otherwise bouncing against the tape. Consequently, the recording/reproducing characteristics of such a device are less than perfect and, to a great extent, are deteriorated. It is believed that such undesirable characteristics can be attributed to the use of the rigid pivot arm which supports the head.